A conductor pin placed between two members to electrically connect the two members to allow conduction therebetween has been conventionally used in various fields or products. For example, various portable electronics devices, such as cellular phones, compact game machines, compact personal computers and PDAs, usually have a structure including a main body of the electronics device and a battery pack for supplying electric power to the main body. In this structure, electric power supply from the battery pack to the main body of the electronics device is carried out, for example, through the conductor pin placed between the battery pack and the main body.
As described in Japanese Unexamined Patent Application No. 2002-56831, for example, such conventional conductor pins are formed to be compressible using a spring. Generally known conductor pins that are formed to be compressible using a spring include, for example, one described in Japanese Unexamined Patent Application No. 2001-283806, which includes a hollow member, a contact slidably accommodated in the hollow member, and a spring for urging the contact housed in the hollow member outward from the hollow member. The contact is formed by a solid member, and the spring is generally formed to press the bottom surface of the contact.
Conductor pins of the type described above, such as one to be placed between the battery pack and the main body of a cellular phone, are required to have very small dimensions. However, conventional conductor pins as described above have difficulty in further size reduction because of their structure. Namely, the above-described conventional conductor pins have a contact formed by a solid member, and the bottom surface of the contact is urged by a spring. Therefore, the entire length of the conductor pin necessarily becomes, at the minimum, a total of the length of the fully compressed spring, a desired sliding distance of the contact (a length by which the conductor pin can be compressed) and the length of the contact, and further reduction of the entire length is impossible.
In order to solve the above-described problem, for example, the contact may be formed by a hollow member with a top panel, and the spring may be inserted in the contact to press the top panel thereof, to reduce the length of the conductor pin by the length of the prior art contact. However, a very small hollow member with a top panel is difficult to be produced, particularly it is difficult to provide dimensional accuracy to the hollow member with a top panel, through a conventional drawing process of a metal plate, which is typically used for producing such hollow members. Further, if the hollow member with a top panel forming the contact is, for example, plated with a metal, the hollow member cannot be produced using a metal plate plated with a metal in advance, since the metal plate is stretched through the drawing process (if a metal plate plated with a metal in advance is used, the metal plating on the stretched metal plate is cracked during the drawing process). On the other hand, if the hollow member with a top panel is plated after the drawing process, it is difficult to provide satisfactory plating on the inner surface of the hollow member because of the very small inner diameter of the hollow member with a top panel. Further, even if the plating could be carried out, the thickness of the plating on the inner surface cannot be measured.
In view of the above-described circumstances, the present invention is directed to provide a conductor pin that is suitable for use as a very small conductor pin used, for example, with cellular phones, has a size smaller than conventional conductor pins and can be produced easily.